Portable electronic devices, such as those configured to be handheld or otherwise associated with a user, are employed in a wide variety of applications and environments. The ubiquity of such devices as mobile phones, wearables, including smart watches and glasses, digital still cameras and video cameras, handheld music and media players, portable video game devices and controllers, tablets, mobile internet devices (MIDs), personal navigation devices (PNDs), other APPlication acCESSORIES (or Appcessories for short) and other similar devices speaks the popularity and desire for these types of devices. Increasingly, such devices are equipped with one or more sensors or other systems for determining the position or motion of the portable device with increasing sophistication and accuracy. Likewise, additional sensing capabilities are commonly available in the form of proximity and ambient light sensors, image sensors, barometers, magnetometers and the like. Still further, such portable devices often feature navigation systems, such as a Global Navigation Satellite Systems (GNSS), that enable precise determinations regarding geophysical position and movement. Corresponding advances in computation power, size, power consumption and prices make such portable devices powerful computing tools with extensive capabilities to detect their environment.
Given the noted popularity in portable devices having some or all of these capabilities, a wide variety of sensor data may be available and therefore leveraged to characterize activities the user in which the user may be engaged. One significant application relates to the operation of moving vehicles, such as for example automobiles. Notably, it may be desirable to assess aspects of how the vehicle is operated, including whether the operation is in a safe and legal manner. In addition, it may be important to determine whether the operator is using the portable device in a manner that distracts from proper operation of the vehicle. Correspondingly, there is a need for techniques to utilize sensor data from a portable device to analyze the performance of vehicle operator. As will be described in the following materials, this disclosure satisfies these and other needs.